Preimplantation Genetic Diagnosis (PGD) in Genetic Screening, Salt Lake City, UT
Preimplantation genetic diagnosis, PGD, was made possible by advances in In vitro fertilization (IVF) which revolutionized infertility treatment and opened the door for many new and exciting technologies. These technologies include intracytoplasmic sperm injection (ICSI) which gave “infertile males” new hope for creating genetically related children. 
PGD is offered by our Salt Lake City, Utah fertility clinic and it provides a means to screen embryos for specific abnormalities prior to uterine transfer in an IVF cycle. PGD can screen for an abnormal number of chromosomes (aneuploidy), chromosomes that are broken or translocated, and specific genetic diseases. Preimplantation genetic diagnosis is extremely accurate in identifying male and female embryos making gender selection, or family balancing, a scientific reality. PGD gives many couples the joy of raising children of both genders.
PGD allows, in addition to gender selection, for preventing transmission of sex linked genetic diseases. These are disorders that can only present in a child of a particular sex. For example, hemophilia A and B are X (female chromosome) linked recessive and can only occur in males (XY). If a woman has the gene for hemophilia, after PGD only female embryos will be transferred to the uterus thus eliminating the chance for hemophilia in the child. Our Salt Lake City, UT PGD program routinely screens for many genetic disorders.
The risk of genetic disorders is directly related to female age. Women over 35 years of age are at higher risk for chromosomal abnormalities, which can lead to early miscarriage or conditions such as Down’s syndrome.
In PGD, one or two cells are removed from the embryo and genetically evaluated in a procedure known as a blastomere biopsy. The biopsy involves removing a small sample of the cells DNA. Initially, the cells have not differentiated and a biopsy can be taken, usually on day 3, without damaging the embryo. Results of the biopsy are typically available within 48 hours. This means that the embryos transferred have the opportunity to develop to the blastocyst stage.
Using PGD, embryos are examined using fluorescent in situ hybridization (FISH) and/or the polymerase chain reaction (PCR). FISH involves labeling chromosomes with fluorescent tagged probes and examining them under a special microscope. These tags allow gender determination, identification of missing or extra chromosomes, and translocations.
PGD using PCR creates multiple copies of specific identified areas of the chromosome and is used to screen for single gene defects. When the genetic disease is present in the parent, a copy of a segment of his/her gene can be used to make a genetic probe. This probe will “identify” the genetic disease if it is present in the embryo.
Our Salt Lake City Utah PGD program can currently screen for more than 120 specific genetic diseases such as Tay Sachs, cystic fibrosis, Fanconi anemia, fragile X syndrome, hemophilia A, and others. As more genetic diseases are characterized, they are added to the list of those which can be screened.
Preimplantation Genetic Screening (PGS), Salt Lake City, UT
We are now offering a new procedure known as preimplantation genetic screening (PGS). Recently (2009) screening has become available through
Gene Security Network for all 24 chromosome pairs in a single blastomere using
state-of-the-art microarray chips. PGS is also an extremely accurate test to determine the sex of the embryos making gender selection possible. Test accuracy is thought to exceed 99%. Please see our PGS page for a complete description of this new and exciting technology.
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